After a six month phase in, New Zealand's ban on single-use plastic bags takes effect tomorrow.
Supermarkets made the switch by the end of last year.
Associate Environment Minister Eugenie Sage says Kiwis really support the move.
She says research found in April last year 56 percent of shoppers surveyed were bringing reusable bags, and that figure rose to 91 percent by September.
"Banning these bags means that we;ll be saving tens of millions of bags going to landfill or getting into rivers and streams and into the oceans, protecting our marine life - fish, seabirds and marine mammals.'
Bin liners, dog poo bags, and the bags used for meat, fruit and vegetables are not included in the ban.
Sage told the Weekend Collective it does include compostable, degradable bags.
"We don't have the facilities around New Zealand to deal with compostable bags, and they don't degrade in home compost heaps."
Sage was unsure about the rules for the stronger plastic bags Countdown has been selling.
Still confused? Here are the five other things you need to know:
There's a precise definition for what's actually banned
The rules apply to any type of plastic less than 70 microns in thickness, that's new or un-used, has carry handles, is provided for carrying sold goods, and is made of bio-based materials like starch. It also covers bags made of plastics that are degradable, biodegradable or oxo-degradable.
These are sometimes marketed as "not plastic". The typical type of bag covered are those offered at supermarkets and stores - the old yellow Pak N Save bags measured about 35 microns, while those from clothing or department stores are usually between 50 and 70 microns.
The bags many people are using now are jute or polypropylene bags, that can be reused over and over.
The Government was encouraging retailers to clarify with their suppliers on the thickness of their bags they offered, and recommended they choose reusable ones.
Over the six-month phase-out period that led up to the law kicking in, supermarkets have already switched away from single-use plastic shopping bags, stopping tens of millions of them from entering circulation.
Kiwis also appear to have adopted the change early, with survey results showing more than 80 per cent of shoppers were bringing their own reusable bags with them as at last September - up from just over half a few months before that.
That said, a Herald survey conducted in central Queen St last week counted what appeared to be five new single-use plastic shopping bags carrying goods out of four shops.
Noel Leeming, Farmers, Daiso Japan, Yummy Jianbing takeaways, Jay Jays, Mirrou and Hannahs all said they would have compliant bags from tomorrow.
The survey counted 25 paper, woven and other types of bags, which would be permitted after Monday.
Many people put smaller purchases in their own bags or into a pocket.
Bio-bags are banned too
Even though bio-based plastic bags are sometimes made from plants, their manufacturing process prevents them from breaking down as quickly or as easily.
Compostable bags, for example, if not composted properly, ended up being a problem too, and not everyone had access to a home compost that could process these bags.
But the Ministry for the Environment has advised that this part of the ban might be revisited if the right infrastructure is developed.
Lots of other types of bags can still be used
People will still be able to buy lightweight barrier bags, like the ones that you get in the deli or butchery, along with bin liners, pet waste bags and nappy bags.
Also exempt were bags used in packaging, like bread bags and pouches for cooked chicken.
The Government's reasoning was that these types of bags were needed for hygiene purposes, and at this stage, it wasn't looking at extending the ban to them.
The rules also didn't apply to long-life synthetic fabric multi-use shopping bags.
These were bags usually between 45 and 75 microns in thickness and made wholly or predominantly of nylon, polypropylene or polyester fabric and designed to be multi-use.
Similarly, there was an exemption for bags certified by an accredited entity as being capable of carrying 5kg over a distance of 100m for a minimum of 55 uses.
The exemption aimed to cover bags made from synthetic fabrics, as these were usually lightweight and often able to be scrunched down to fit inside a pocket, backpack or handbag.
The rules will be enforced
While the Government doesn't have any targets to prosecute businesses that flout the laws, it has promised that breaches will be enforced.
There have been warnings that retailers could face six-figure fines, although a court would need to determine a penalty if a prosecution was sucessful.
However, the ministry has pointed out that it wanted to focus more on working with businesses to encourage compliance.
In the event that someone contacted the ministry to tell them about a breach, officers would contact the business and work with them to find out why they hadn't stopped giving out banned bags.
The ministry also planned to begin random retail precinct audits to assess levels of compliance and advise retailers where changes were required.
The ban is a first step
Estimates suggest that, over recent times, the average Kiwi had been using 154 single-use plastic shopping bags each year.
That equated to around 750 million bags per year, or about 0.01 per cent of the total weight of waste that went into levied landfills - if they didn't end up polluting our environment first.
"Lightweight single-use plastic shopping bags pollute nature because they are easily transported by wind and water," Associate Environment Minister Eugienie Sage said.
"The phase-out encourages people to act with nature in mind."
But while widespread, these bags were only a small subset of all sources of marine plastics.
Plastics currently made up an estimated 80 to 85 per cent of marine litter, and once in our oceans, they eventually broke down into microplastics, which could in turn enter the foodchain and cause myriad other problems.
The Government has signalled that the new measures are simply a first step to tackling the larger issue that is the "throwaway culture" of our linear economy, and moving to a circular economy where little gets thrown out or wasted.